Currently, the 3rd Generation Partnership Project (3GPP) standardization organization and non-3GPP standardization organizations are developing a new access mode which is known as Home Access (HA). User Equipment (UE) uses authorized spectrum and a generic Internet Protocol (IP) access network such as Digital Subscriber Line (DSL) and Cable Broadband (CB) to get connected to the mobile network of the operator through a home Wireless Access Point (WAP).
A CSG mechanism is introduced in order to restrict the UE from accessing a specific home WAP or a specific WAP. The CSG identifies UEs (or users) authorized to access one or more cells of a operator, but restricts other UEs from accessing such cells. A CSG area includes one or more cells, which are identified by a CSG identifier (ID). A CSG area is accessible to a group of UEs, but not accessible to other UEs than this group. The CSG IDs of all CSG areas accessible to a UE form an allowed CSG list, which is also known as a CSG white list. The allowed CSG list is stored in the UE, and is obtained after the UE gets registered onto the network.
In the process of practicing the prior art, the inventor of the present application finds that after the UE gets registered onto the network, the CSG information (such as allowed CSG list) of the UE may change but the UE is unaware of the change, which makes the user unable to access the allowed CSG area correctly.
Meanwhile, after the CSG information of the UE changes, the accessed CSG area by the UE is no longer accessible to the UE. The prior art provides no solution to detaching the UE from the accessed CSG area.